Journals >Acta Photonica Sinica
Contents
2010
Volume: 39 Issue 9
36 Article(s)
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Research Article
Thermal Management of Laser Diode Pumped Nd Doped Glass Disk Amplifier
HOU Li-qun, FAN Zhong-wei, QIU Ji-si, ZHAO Tian-zhuo, ZHANG Jing, ZHANG Xiao-lei, and TANG Xiong-xin
Based on the fundamental theory of heat transmission, the transient thermal and stress distributions of laser gain medium in a laser diode end-pumped Nd doped glass disk amplifier are studied by means of finite element analysis. The cooling characteristics of glass disk on different boundary conditions in repetition moBased on the fundamental theory of heat transmission, the transient thermal and stress distributions of laser gain medium in a laser diode end-pumped Nd doped glass disk amplifier are studied by means of finite element analysis. The cooling characteristics of glass disk on different boundary conditions in repetition mode are also discussed. Furthermore, three kinds of different thermal management schemes are proposed with the progress and their thermal effect characteristics are compared. The simulation results show that the cooling configuration with transparent sapphire plate adjacent to the pumping surface which is mounted with TEC-cooled copper housing outside is much attractive. The peak temperature about 120℃ occurs in the centre of non-pumping surface. Although its cooling ability is not much effective as that of direct water cooling but it can avoid some problems brought out by the latter. The simulation analysis also proves that the heat within glass disk is difficult to be taken away radially because of its large heat resistance. In practice, the thermal management system should be designed to cool glass disk along axis direction..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1537 (2010)
Optimal Simulation for the Thickness Uniformity of the Film Deposited by Pulse Laser Sputtering
WANG Sheng, YE Jing-feng, LIU Jing-ru, BAI Ting, YE Xi-sheng, and WANG Li-jun
Method of off-axis rotated scan is studied in order to improve the thickness uniformity of the film by pulse laser deposition (PLD). Based on the principle and spatial distribution of plasma, radial distribution formula of film thickness is formed. Effects on uniformity of film deposited by method of off-axis rotated sMethod of off-axis rotated scan is studied in order to improve the thickness uniformity of the film by pulse laser deposition (PLD). Based on the principle and spatial distribution of plasma, radial distribution formula of film thickness is formed. Effects on uniformity of film deposited by method of off-axis rotated scan are simulated numerically. The simulated results show that optimize of d (distance between sputtering dot and foundation) and r (interval between particle center and foundation center ) are primary means for improving the uniformity of film. In addition, influence of electromotor rotate speed, working time and laser repetition frequency is considered. Simulated with optimal parameters, maximum radius of film diameter over 40 mm is obtained when 95% uniformity is required..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1543 (2010)
Preparation and Luminescence Properties of Eu3+ Doped TiO2 Nano-powder
LIU Guo-jing, HU Xiao-yun, PAN Jing, ZHANG De-kai, YE Yan-xi, YAN Zhi-yun, FAN Jun, and LI Fei
Four different formulas of the Eu3+ doped TiO2 nano-crystals are prepared by the sol-gel method, using tetrabutyl titanate as the precursor. The morphology, composition and properties of the luminous samples are characterized by the SEM, EDS and PL spectra. And also the effects and mechanism of annealing temperature, mFour different formulas of the Eu3+ doped TiO2 nano-crystals are prepared by the sol-gel method, using tetrabutyl titanate as the precursor. The morphology, composition and properties of the luminous samples are characterized by the SEM, EDS and PL spectra. And also the effects and mechanism of annealing temperature, mole fraction of the Eu3+ ions doped and the quantity of ethanol on the luminous intensity are analyzed respectively. The results show that the samples are homogeneusly doping, and the particle size is about 30~80 nm. The EDS spectra show that the Ti∶O atomic ratio is not based on the number of stoichiometric TiO2 to meet the ratio 1∶2, for the formation of Ti-O-Ti bond in TiO2, Eu3 + is likely to replace the Ti4+, at the same time the oxygen vacancies is formed, which indicates that the rare earth of Eu3+ entered into TiO2 lattices. The PL spectra of nano-crystal TiO2∶Eu3+ show the strongest red emission intensity at 614 nm(5D0→7F2), simultaneously, the sample emission peak at 593 nm(5D0→7F1), which is classified to the magnetic dipole transition. In addition, annealing temperature and the quantity of ethanol have important effects on the emission intensity..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1547 (2010)
Ceramics Fabricated with Nano-powders by Different Preparation Methods
LU Shen-zhou, YANG Qiu-hong, and ZHANG Hao-jia
Nd∶(Y0.9La0.1)2O3 transparent ceramics are fabricated with wet-chemical composite nano-powders and solid-state reaction nano-powders, respectively. Their microstructure, optical and spectral properties are investigated. The experimental results show that both samples own the same spectroscopic properties, while the samNd∶(Y0.9La0.1)2O3 transparent ceramics are fabricated with wet-chemical composite nano-powders and solid-state reaction nano-powders, respectively. Their microstructure, optical and spectral properties are investigated. The experimental results show that both samples own the same spectroscopic properties, while the samples fabricated by wet-chemical composite nano-powders have better optical properties due to the uniform mixing of the raw materials. The worse performances of the samples fabricated with solid-state reaction nano-powders are ascribed to the inhomogeneous dispersion of La2O3 in the processing of mechanical ball-milling, which cause unevenly grains and few left pores. Long time ball-milling will deteriorate the optical properties of the samples prepared by solid-state reaction method..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1553 (2010)
Organic Vapor Sensing Methods Based on Silver Triangular Nano-prisms
MA Wen-ying, YANG Huan, YAO Jun, LIU Juan-yi, LI Fei, and TANG Dong-sheng
A metal nanostructure sensing method for monitoring organic vapors is presented. A kind of triangular silver nanoprisms array with relatively high refractive index sensitivity is designed and analysed by finite difference time domain numerical method, and it is fabricated through nanosphere lithography fabrication methA metal nanostructure sensing method for monitoring organic vapors is presented. A kind of triangular silver nanoprisms array with relatively high refractive index sensitivity is designed and analysed by finite difference time domain numerical method, and it is fabricated through nanosphere lithography fabrication method. Experiment results show that the fabricated nanostructures array is so sensitive to ethanol molecules that the detecting sensitivity reaches as high as 24ppm/nm. This organic vapor sensing method is expected to have a great potential in environmental monitoring..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1557 (2010)
Effect of the Change of Surface Structure of Photonic Crystals on Intensity of Transmitted Light
MAO Yu, and TONG Yuan-wei
The photonic crystals of hexagonal structure with GaAs circle rods are taken as examples to illuminate dependence of intensity of transmitted light on the change of surface structure of the PC. Simulation with finite difference time domain method shows that the change of radius of outside rods and the displacement of tThe photonic crystals of hexagonal structure with GaAs circle rods are taken as examples to illuminate dependence of intensity of transmitted light on the change of surface structure of the PC. Simulation with finite difference time domain method shows that the change of radius of outside rods and the displacement of the outermost layer circle rods will have effect on intensity of negative transmitted light, in frequency range where negative refraction exist for the same photo crystal..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1562 (2010)
Two Components Vector Spatial Solitons in Two-photon Photorefractive Crystals
SU Yan-li, JIANG Qi-chang, and JI Xuan-mang
To study the vector spatial solitons in biased two-photon photorefractive crystals, the dynamical evolution equation and the numerical solution of the vector spatial solitons are established. The bright-bright and dark-dark self-coupled vector solitons are predicted by using numerically methods. The dynamical evolutionTo study the vector spatial solitons in biased two-photon photorefractive crystals, the dynamical evolution equation and the numerical solution of the vector spatial solitons are established. The bright-bright and dark-dark self-coupled vector solitons are predicted by using numerically methods. The dynamical evolutions of the bright-bright self-coupled vector spatial solitons are analyzed numerically. The results indicate that these self-coupled vector solitons can be obtained by using simple numerical integration procedures and their formation are irrespective to the ratio of the intensities of the two optical components. The bright-bright and dark-dark self-coupled vector spatial solitons exist steadily in two-photon photorefractive crystals..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1567 (2010)
Filtering Properties of One Dimensional Tunable Magnetized Plasma Photonic Crystals with Single Defective Layer
ZHANG Hai-feng, ZHENG Jian-ping, and XIAO Zheng-quan
The plasma rising time, plasma temperature and plasma density are taken as the tunable parameters, under the isothermal hypothesis. The piecewise linear current density recursive convolution finite-difference time-domain method for magnetized plasma is applied to study the filtering properties of one dimensional tunablThe plasma rising time, plasma temperature and plasma density are taken as the tunable parameters, under the isothermal hypothesis. The piecewise linear current density recursive convolution finite-difference time-domain method for magnetized plasma is applied to study the filtering properties of one dimensional tunable magnetized plasma photonic crystals with single defective layer. The electro-magnetic propagation process of a Gaussian pulse through a magnetized plasma photonic crystal is investigated. The transmission coefficients through magnetized plasma photonic crystals are calculated based on which the effects of the plasma rising time, plasma temperature and plasma density on characteristic of filtering are analyzed. The results illustrate that the filter channel can be tuned by changing rising time and plasma density and the resonant frequency can not be tuned by changing plasma temperature..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1572 (2010)
Surface Error Compensation of Off-axis Parabolic Mirrors by Alignment
CHEN Qin-fang, LI Ying-cai, MA Zhen, LI Xu-yang, and GUO Yong-xiang
In order to improve the imaging quality of optical system, high precision surface of mirrors are put forward to improve their imaging quality. It makes their fabrication harder. Wavefront aberration induced by alignment is analyzed in off-axis parabolic mirror system based on the wavefront aberration theory. The surfacIn order to improve the imaging quality of optical system, high precision surface of mirrors are put forward to improve their imaging quality. It makes their fabrication harder. Wavefront aberration induced by alignment is analyzed in off-axis parabolic mirror system based on the wavefront aberration theory. The surface error of off-axis parabolic mirror can be compensated by alignment so it will reduce the fabrication difficulty, shorten its period and save its cost. In the simulations of an off-axis parabolic mirror with surface error λ/40 RMS (λ=632.8 nm) ( Root Mean Squre) with ZEMAX software, the figure accuracy is under λ/40 RMS after alignment. It shows that surface error of off-axis parabolic mirrors could be compensated effectively by alignment..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1578 (2010)
Effects of Ultraviolet-B Radiation on Plant Light Energy Transfer Process
LIU Xiao, HE Jun-fang, JI Qian-ru, and YUE Ming
To clarify the effects of Ultraviolet-B (UV-B, 280-315 nm) treatment on the energy transfer process in photosynthesis, steady-state absorption and fluorescence techniques are performed on thylakoid membrane and photosystem II (PSII).The results show that under greenhouse, lower UV-B radiation levels do not inhibit lighTo clarify the effects of Ultraviolet-B (UV-B, 280-315 nm) treatment on the energy transfer process in photosynthesis, steady-state absorption and fluorescence techniques are performed on thylakoid membrane and photosystem II (PSII).The results show that under greenhouse, lower UV-B radiation levels do not inhibit light energy transfer process. Plant ensures energy reach to reaction center through a series of adjustment mechanism. These mechanisms include enhancement of absorb intensity of short-wavelength-absorption pigments, regulation of energy distribution between two photosystems and the changs of conformation and (or) location about pigment-protein system..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1582 (2010)
Investigation and Validation of the Reconstruction Algorithm for Small Animal Cone-beam CT Imaging
MIAO Hui, WANG Qiu-yin, ZHAO Hui-juan, WANG Ting-ting, and GAO Feng
Simulation for cone beam CT system and the 3D Shepp-Logan Model is carried out.FDK reconstruction algorithm is developed to reconstruct the images and then evaluated with the 3D Shepp-Logan Mode.Experiments are carried out on a constructed cone beam CT system and a homemade phantom.Simulation and experimental reconstruSimulation for cone beam CT system and the 3D Shepp-Logan Model is carried out.FDK reconstruction algorithm is developed to reconstruct the images and then evaluated with the 3D Shepp-Logan Mode.Experiments are carried out on a constructed cone beam CT system and a homemade phantom.Simulation and experimental reconstruction results indicate that reconstruction algorithm can faithfully provide both the position and relative contrast of the inner objects.The spatial resolution of the central image from simulation data can reach 8 linepairs/mm..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1588 (2010)
A Finite-Difference-Method Solution to Two-dimensional Steady-State Radiative Transfer Equation
JIN Meng, GAO Feng, LI Jiao, and ZHAO Hui-juan
A novel finite difference method (FDM) solution to the 2-dimensional time-independent radiative transfer equation (RTE) is proposed for small-animal imaging applications, which is based on the real physics of 3-dimensional scattering of a photon in turbid medium. The influences of the angular discretization and the spaA novel finite difference method (FDM) solution to the 2-dimensional time-independent radiative transfer equation (RTE) is proposed for small-animal imaging applications, which is based on the real physics of 3-dimensional scattering of a photon in turbid medium. The influences of the angular discretization and the spatially meshing grids on the accuracy of FDM-RTE solution are investigated and a comparison is made between the FDM-RTE calculations to the relevant Monte-Carlo simulation ones for a validation of the proposed method. The comparison shows that, as the number of the discretized solid angles is over 80, the accuracy of the FDM-RTE calculated forward photon density is insensitive to the spatially meshing grids on the transmission and side surfaces but on the reflection surface. This study provides a viable methodology to the development of the RTE-based Diffuse Optical Tomography(DOT) technology..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1594 (2010)
Enhanced Transmission Through Periodic H-shaped Arrays
SUN Mei, XING Su-xia, CHEN Yuan-yuan, and XU De-gang
An enhanced near infrared transmission through periodic H-shaped arrays in metallic thin films is presented.The sample is fabricated by electron beam lithography and reactive ion etching system.The 0.5-mm-thick quartz substrate is deposited with a 120-nm-thick Au film and a 5-nm-thick chromium adhesion layer.The overalAn enhanced near infrared transmission through periodic H-shaped arrays in metallic thin films is presented.The sample is fabricated by electron beam lithography and reactive ion etching system.The 0.5-mm-thick quartz substrate is deposited with a 120-nm-thick Au film and a 5-nm-thick chromium adhesion layer.The overall size of the sample is about 40×40 μm2,which is composed of 30×30 periodic H-shaped arrays.The period of the H-shaped lattice is 1.1 μm.The arm length of H-shaped is 500 nm and the line width is 120 nm.A broad transmission band centered at about 1.6 μm is found and the transmission coefficient can be as high as about 16.3% for a line width of 120 nm.A simulation by using transfer matrix method (TMM) reproduces quite well the obtained transmission spectrum.Polarization measurements of H-shaped arrays are also demonstrated.The results prove the important role of localized surface plasmon (LSP) in enhanced transmission through the special structure..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1602 (2010)
Distribution Characteristics in the Underwater Inhomogeneous Illumination Field
XU Hong-mei, ZHANG Zhi-gang, and ZHENG Bing
An underwater image detection theory of inhomogeneous illumination field is proposed to reduce the backward of scattered background noise. The distribution function of inhomogeneous illumination field is derived. It is related to receive aperture, distance between target and receiver as well as seawater volume attenuatAn underwater image detection theory of inhomogeneous illumination field is proposed to reduce the backward of scattered background noise. The distribution function of inhomogeneous illumination field is derived. It is related to receive aperture, distance between target and receiver as well as seawater volume attenuation coefficient. An underwater image detection system with distributive light of central power is developed. The tank contrast experiment is proposed, which verifies the inhomogeneous illumination field′s distribution characteristics and underwater probing characteristics. It can clearly distinguish 1 mm details at 0.6 times visibility and identify targets outlined at one times visibility, as well as detect the target at 1.5 times visibility.The underwater system based on inhomogeneous illumination field theory is effective to overcome the influence of backward scattered background noise. These results suggest that this system has a far detection distance, wide visual angle, full view depth and good image definition..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1606 (2010)
Electromagnetically Induced Left Handedness in Y-type Four Level Atomic System
ZHANG Zhen-qing, LIU Zheng-dong, ZHENG Jun, and ZHAO Shun-cai
The quantum system with an interaction between a closed Y-type four-level atom and multi-mode light fields is adopted to possess left handedness by means of the technique of quantum coherence. In the representation of interaction, the density matrix method is utilized in view of the rotating-wave approximation and the The quantum system with an interaction between a closed Y-type four-level atom and multi-mode light fields is adopted to possess left handedness by means of the technique of quantum coherence. In the representation of interaction, the density matrix method is utilized in view of the rotating-wave approximation and the di-pole approximation.The conclusion of the numerical simulation shows that under the appropriate parameter conditions, the medium can achieve negative permittivity and negative permeability simultaneously (i.e. the left handedness effect happens and the left-handed material is realized.) In the condition of the weak probe field, when the Rabi frequency of probe light increases, the frequency range of the medium to achieve its left-handed effect decreases and the refractive index and absorption coefficient will also changed correspondingly. The medium to affect light absorption and gain in the conditions of the establishment of left -handed effect are also discussed. The paper can be concluded that, in the conditions of weak probe field, the electro-magnetic induction can be used to achieve the left-handed effect of the medium, which extends the implementation of left-handed materials in the experiment, and extends the application field of electro-magnetic induction..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1611 (2010)
Quantum Identification Scheme of Cross-center Based on W-state
LI Yuan-hua, LIU Jun-chang, and NIE Yi-you
Using the quantum teleportation and quantum entanglement swapping, a quantum identification scheme of Cross-center based on W-state is proposed, and the identification for user in distributed network is realized. The scheme includes register phase and authentication phase, and the whole system consists of main server aUsing the quantum teleportation and quantum entanglement swapping, a quantum identification scheme of Cross-center based on W-state is proposed, and the identification for user in distributed network is realized. The scheme includes register phase and authentication phase, and the whole system consists of main server and client server. All the operations of any user are processed at client server and there is no direct communication between user and main server. All authentications are processed by servers based on the principles of quantum mechanics, and its security is guaranteed by quantum mechanism. Finally, the security of the quamtum identification scheme is analyzed..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1616 (2010)
Quantum Entanglement of the Coherent State Field Interacting with a Λ Type Three-level Atom Without Rotating Wave Approximation
XIA Jian-ping, REN Xue-zao, CONG Hong-lu, JIANG Dao-lai, and LIAO Xu
Applying the method of coherent-state orthogonalization expansion, the quantum entropy of the coherent state light field interacting with a Λ type three level atom is caculated accurately without rotating wave approximation. The influences of the couplings, mean photon number and the atom in different levels at the iniApplying the method of coherent-state orthogonalization expansion, the quantum entropy of the coherent state light field interacting with a Λ type three level atom is caculated accurately without rotating wave approximation. The influences of the couplings, mean photon number and the atom in different levels at the initial time on quantum entanglement are studied via quantum entropy theory. The results obtained from using the numerical method show that when atom is initially in the excited state, the entanglement reaches the maximum value in a short time, with the increase of the mean photon number, the period of entanglement evolution becomes clearly. The degrees of enganglement in a short time become lower due to the atom is initially in the superposition state of all three levels. Compared with the results of using the method of rotating wave approximation, the contribution of the without rotating wave approximation terms increase notably and the quantum entanglement curvies displays small zigzag-shaped oscillation, with the increasing of couplings and mean photon number..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1621 (2010)
Teleportation of Four Particles W State Through Two EPR States
MA Gang-long, and ZHA Xin-wei
In order to reduce the measurement times and computation of quantum teleportation, a scheme for teleportation of four-particle W state via two EPR states is proposed. The sender Alice only do one orthogonal complete basises measurement on her own particles in the unknown Four-particles and two EPR states, by the means In order to reduce the measurement times and computation of quantum teleportation, a scheme for teleportation of four-particle W state via two EPR states is proposed. The sender Alice only do one orthogonal complete basises measurement on her own particles in the unknown Four-particles and two EPR states, by the means of 16 orthogonal complete measure basises. Then the sender inform the 16 kinds of measurement results to the receiver by classical channel, the receiver introduce two auxiliary particle B3B4, and do some proper transformation(Toffoli gate, C-Not gate, Pauli-X gate, and Pauli-Z gate) on his own particles. As a result, the 16 kinds of collapse modes will be all restored. In other words, the teleportation of four-particle W state is completely realized. Based on quantum mechanics of superposition operator and the transformation operator, the collapses states can be easily obtained, and Bob′s unitary transformation can also be easily given. Because of using orthogonal complete measurement basises method, the sender only need to do a little measurement. This scheme only need one orthogonal complete basises measurement and a simply unitary transmission, which can be realized easily..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1627 (2010)
Quantum Properties of the Field in the System of Λ-type Three-level Atom Interacting with Two-mode Coherent Light Field
LU Dao-ming
Considering two Λ-type three-level atoms initially in the entangled state, one atom is poured into the cavity and interacts with a two-mode cavity. The squeezing and antibunching effects of the field are investigated. The influences of the selective atomic measurement and the intensity of the coherent field, which inteConsidering two Λ-type three-level atoms initially in the entangled state, one atom is poured into the cavity and interacts with a two-mode cavity. The squeezing and antibunching effects of the field are investigated. The influences of the selective atomic measurement and the intensity of the coherent field, which interacts with atom on squeezing and antibunching effect of the field, are discussed. The results obtained by numerical calculations show that squeezing and antibunching effect of the field can be strengthened through selective atomic measurement for atom outside of the cavity..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1631 (2010)
Entanglement Properties of Two Entangled Atoms Without Rotating Wave Approximation
JIANG Dao-lai, REN Xue-zao, CONG Hong-lu, and LIAO Xu
Applying the method of coherent-state orthogonalization expansion, the influnences of dipole-dipole interaction and the coupling strength on the entanglement between two atoms of the Tavis-Cummings model without rotating wave approximation(without-RWA) are studied. Compared with the rotating wave approximation(RWA), itApplying the method of coherent-state orthogonalization expansion, the influnences of dipole-dipole interaction and the coupling strength on the entanglement between two atoms of the Tavis-Cummings model without rotating wave approximation(without-RWA) are studied. Compared with the rotating wave approximation(RWA), it is found that the entanglement of the without-RWA agree with that of RWA when the coupling strength is weak. In the strong coupling regime, the sudden death phenomena occurs. The results also show that the stronger the atom-field coupling strength is, the longer the state stays in the disentangled separable state, which means that the length of the time interval for the distanglement depends on the atom-field coupling strength. When the dipole-dipole interacton is taken into account, the entanglement of the two atoms will be enhanced with the increace of dipole-dipole interaction..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1636 (2010)
Illumination Compensation Based on Direction Filter and Self Quotient Image
WANG Jing, and SU Guang-da
A new method is proposed to process facial image in bad lighting condition instantly.Based on simplified 3-D face illumination model,direction filter is used to weaken the attached shadow,and gaussian low pass filter is used to weaken the casted shadow.Image quality is greatly improved by the non-linear combination of A new method is proposed to process facial image in bad lighting condition instantly.Based on simplified 3-D face illumination model,direction filter is used to weaken the attached shadow,and gaussian low pass filter is used to weaken the casted shadow.Image quality is greatly improved by the non-linear combination of the two methods.Experiment results demonstrate that the robust face recognition rate can be improved effectively by the proposed method under bad lighting conditions..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1641 (2010)
Image Contourlet Threshold De-noising Based on Chaotic Particle Swarm Optimization
WU Yi-quan, and JI Shou-xin
A method of the image Contourlet threshold de-noising based on chaotic particle swarm optimization is proposed. This method can acquire the optimal threshold using chaotic particle swarm optimization in the Contourlet transform domain and then remove the noise by soft threshold function. It does not need the prior infoA method of the image Contourlet threshold de-noising based on chaotic particle swarm optimization is proposed. This method can acquire the optimal threshold using chaotic particle swarm optimization in the Contourlet transform domain and then remove the noise by soft threshold function. It does not need the prior information of noise variance. The experimental results show that this method can effectively eliminate the mixed Gaussian white noise and Pepper Salt noise , increase the peak signal to noise ratio(PSNR) and preserve the images details and texture well compared with the de-noising methods of Bayesian wavelet threshold, wavelet threshold by particle swarm optimization and adaptive Contourlet threshold. So the proposed method can improve significantly image visual effect..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1645 (2010)
Point Spread Function and Optical Transfer Function of Bind Deconvolution in Face Detection
SHEN Bi-chuan, and WU Yan
The optical diffraction,defocus,and sampling effects are investigated in the high speed real-time face detection system.Through the analysis,their point spread function (PSF) and optical transfer function (OTF) are formulated to characterize the optical system in the spatial and frequency domain respectively.With the aThe optical diffraction,defocus,and sampling effects are investigated in the high speed real-time face detection system.Through the analysis,their point spread function (PSF) and optical transfer function (OTF) are formulated to characterize the optical system in the spatial and frequency domain respectively.With the approximate priory knowledge of their PSF,two integer focus operators are proposed and their OTFs to those of Laplacian and the optimal focus operator are compared.This system utilizes a motorized focusing mechanism to acquire high resolution images and a sinc interpolation at the preprocess stage.The demonstration system reaches 15.6 fps with satisfactory results and validates the theoretical analysis..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1652 (2010)
Remote Sensing Image Denoising Algorithm Based on Fusion Theory Using Cycle Spinning Contourlet Transform and Total Variation Minimization
ZHAO Jie, and YANG Jian-lei
In order to solve the problem that most of existing image denoising methods insufficiency preserve the details and enhance edges while implementing denoising, a new method for remote sensing image denoising is proposed, based on a combination of cycle spinning contourlet transform (CT), and the total variation (TV) minIn order to solve the problem that most of existing image denoising methods insufficiency preserve the details and enhance edges while implementing denoising, a new method for remote sensing image denoising is proposed, based on a combination of cycle spinning contourlet transform (CT), and the total variation (TV) minimization scheme. The proposed method relies on principles that CT scheme is well suited for preserving detailed and fine textures information of original image while TV minimization denoising scheme is capable of enhancing sharpened significant edges while denoising, therefore to fuse the two schemes using the proposed fusion rule can achieve better results. Compared with several commonly used approaches, the experimental results show that this novel algorithm is capable of reducing Gibbs phenomenon and staircase effect produced by CT and TV denoising methods respectively, superior both in visual quality of denoising and Peak Signal to Noise Ratio (PSNR), and preserves more spectral information and less spectral distortion simultaneously..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1658 (2010)
Texture Segmentation and Boundary Recognition of Wire Rope Images in Complicated Background
SUN Hui-xian, ZHANG Yu-hua, and LUO Fei-lu
In order to detect the boundary of wire rope exactly in visual inspection of surface defection, a novel texture segmentation and boundary recognition method is proposed. The fuzzy Hough transform is used to detect the direction of rope texture. A new texture feature is proposed based on the Edge Direction Density HistoIn order to detect the boundary of wire rope exactly in visual inspection of surface defection, a novel texture segmentation and boundary recognition method is proposed. The fuzzy Hough transform is used to detect the direction of rope texture. A new texture feature is proposed based on the Edge Direction Density Histogram (EDDH). The EDDH is weighted based on the direction of rope texture in Fuzzy C-Means clustering segmentation. The boundary of wire rope is recognized preliminary to detect parallel lines in the map of membership by Hough transform. Moreover, an adaptive boundary correction method is presented to confirm the boundary exactly. The results of texture segmentation and boundary recognition by the proposed method are compared with the results of Gray Level Co-occurrence Matrix (GLCM) and Local Binary Pattern (LBP) respectively. The experimental results show that the proposed method can realize wire rope image segmentation and boundary recognition effectively, and its performance is better than the GLCM′s and LBP’s..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1666 (2010)
Dual-tree Complex Wavelet Transform for Infrared Dim Target Background Suppression
ZHANG Xiang, ZHANG Jian-qi, QIN Han-lin, and LIU Jing
In order to solve the structured background suppression which is a difficult problem for infrared dim target detection technique,a method of infrared dim target background suppression based on DT-CWT is presented,considering the shift invariance,directional selectivity and perfect reconstruction of dual-tree complex waIn order to solve the structured background suppression which is a difficult problem for infrared dim target detection technique,a method of infrared dim target background suppression based on DT-CWT is presented,considering the shift invariance,directional selectivity and perfect reconstruction of dual-tree complex wavelet transform (DT-CWT),Firstly,the image is decomposed by DT-CWT to extract the multi-scale detail characteristics,then wavelet coefficients of each decomposed level is adjusted nonlinear with a Max-Median filter to change the target strength,and the estimated background image is obtained by wavelet reconstruction.The result image is obtained by subtracting the background image from the original image.Based on the real IR image sequences,the experimental results demonstrate that compared with the two-dimensional least mean square error method,the presented method has good effects both in the subjective vision and numerical indices..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1672 (2010)
A Novel Hilbert Transform Algorithm for Phase Evaluation from Fringe Pattern
XIONG Liu-dong, JIA Shu-hai, and DU Yan-fen
A novel Hilbert transform algorithm for detecting phase from fringe pattern is proposed.Only one interference pattern is required for the phase evaluation.In practice,the Hilbert transform based on the Fourier transformation eliminates all negative frequency components,and any phase variation in the fringe pattern haviA novel Hilbert transform algorithm for detecting phase from fringe pattern is proposed.Only one interference pattern is required for the phase evaluation.In practice,the Hilbert transform based on the Fourier transformation eliminates all negative frequency components,and any phase variation in the fringe pattern having negative local spatial frequency can not be correctly reconstructed.A procedure for detection of regions having zero spatial frequency in the fringe pattern is proposed by an estimation function for complicated phase distribution.A binary matrix is used for modifying wrapped phase of complicated phase distribution fringe pattern, and a method for removing the bias component by twice Hilbert transform is proposed.The correct values of phase is obtained by an unwrapping process.The performance of the proposed method is evaluated by computer simulation..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1678 (2010)
Polarization Image Fusion Approach Based on Non-Negative Matrix Factorization and IHS Color Model
ZHOU Pu-cheng, HAN Yu-sheng, XUE Mo-gen, WANG Feng, and ZHANG Lei
To overcome the drawback of conventional false color fusion methods for polarization images, a image fusion approach based on non-negative factorization and IHS(Intensity Hus Saturation)color model is presented. Firstly, all of the polarization parameter images obtained by polarization information analysis are taken asTo overcome the drawback of conventional false color fusion methods for polarization images, a image fusion approach based on non-negative factorization and IHS(Intensity Hus Saturation)color model is presented. Firstly, all of the polarization parameter images obtained by polarization information analysis are taken as source data set for non-negative matrix factorization, so as to extract three feature basis images containing most of the polarization information of the object. Then, after histogram matching, these three feature basis images are mapped into three color channels of IHS color model. Finally, the fused image is achieved after the transform from IHS to RGB color model. Experiment results have shown that, the proposed method has better color representation capability, and effectively pops out detailed information of objects, and enhances its readability..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1682 (2010)
Image Fusion Based on Data Assimilation and Differential Evolution Algorithm
SHI Liang-wu, LIN Li-yu, WANG Si-chun, and CHEN Rong-yuan
In order to solve the problem that fusion rules of existing image fusion methods can not be adjusted adaptively according to successive application target of the fusion image, and advantages of different fusion algorithm can not be integrated, an image fusion framework based on data assimilation and differential evolutIn order to solve the problem that fusion rules of existing image fusion methods can not be adjusted adaptively according to successive application target of the fusion image, and advantages of different fusion algorithm can not be integrated, an image fusion framework based on data assimilation and differential evolution algorithm (DE) is proposed. In this framework, nonsubsampled contourlet transform is used as model operator and discrete wavelet transform with DBSS(2,2)as observer operator. The objective function is composed of weight sum of indices, which are determined according to their relations with following application, and DE is employed to obtain proper image. Two groups of experiments with the help of the quantitative parameters(entropy, average gradient, standard deviation spatial frequency and interactive entropy of rms)and visual analysis verify feasibility of the framework..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1688 (2010)
Concrete CT Image Modified Metropolis Dynamics Segmentation Method Based on Markov Random Field
ZHAO Liang, LI Chang-hua, DANG Fa-ning, CHEN Deng-feng, and XU Sheng-jun
A Modified Metropolis Dynamics (MMD) simulated annealing algorithm based on Markov Random Field (MRF) is proposed. Threshold α of the proposed algorithm optimized Metropolis arithmetic. Based on the Beyes theory, the segmentation issue is transformed to the Maximum A Posteriori (MAP) and the parameter prediction algoriA Modified Metropolis Dynamics (MMD) simulated annealing algorithm based on Markov Random Field (MRF) is proposed. Threshold α of the proposed algorithm optimized Metropolis arithmetic. Based on the Beyes theory, the segmentation issue is transformed to the Maximum A Posteriori (MAP) and the parameter prediction algorithm is provided. In the experiment, the proposed algorithm is compared with the traditional Metropolis algorithm, the Gibbs sampler and Iterated Conditional Mode (ICM), and the results show that the segmentation efficiency and segmentation accuracy of the proposed algorithm improve obviously. Through concrete CT image segmentation experiment, it is also found that the inner structure and defect of the concrete materials can be integrally reflected based on MMD..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1693 (2010)
Construction of Complex Contourlet Packet Transform and Its Application to Image Denoising
WANG Yong-sheng, and FU Yong-qing
Considering the normal contourlet transform only decomposed the low frequency coefficients of the signals, and ignored the high frequency coefficients, a novel complex contourlet packet transform is constructed by combining the analytic dual-tree complex wavelet packet transform and nonsubsampled directional filter banConsidering the normal contourlet transform only decomposed the low frequency coefficients of the signals, and ignored the high frequency coefficients, a novel complex contourlet packet transform is constructed by combining the analytic dual-tree complex wavelet packet transform and nonsubsampled directional filter banks. Then a complex contourlet packet image denoising algorithm based on neighbouring thresholding classification is proposed. The new transform has good characteristics of multiresolution, localization, directionality and anisotropy, as well as translation invariance. Furthermore, it has more abundant direction components. The experimental result shows that the complex contourlet packet transform can restrain Gibbs-like artificial around edges in the course of denoising, and preserve more details and textures of the images efficiently. The PSNR and the visual quality of this algorithm are also superior to the traditional methods..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1697 (2010)
An Algorithm of 3DSPIHT in Conjunction with ROI for Hyperspectrum Image Compression
MA Dong-mei, MA Cai-wen, and WANG A-ni
A compression algorithm based on 3D-DWT and 3DSPIHT in conjunction with ROI is proposed for hyperspectral images of LASIS according to its interference hyperspectral properties. Firstly, the hyperspectral image sequence with asymmetric 3D-DWT is decomposed. Secondly, its major hyperspectrum coefficients are scaled up bA compression algorithm based on 3D-DWT and 3DSPIHT in conjunction with ROI is proposed for hyperspectral images of LASIS according to its interference hyperspectral properties. Firstly, the hyperspectral image sequence with asymmetric 3D-DWT is decomposed. Secondly, its major hyperspectrum coefficients are scaled up by ROI method to protect the hyperspectral information. Finally, the general 3DSPIHT algorithm is adapted to encode the transformed images. The numerical experiment results show that the PNSR is more than 40 dB at 8∶1 compression rate, and the hyperspectral information can be protected..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1702 (2010)
An Algorithm for Detecting Bills′ Watermarks Based on Prior Information and Multi-template Matching
XIE Jian-bin, LIU Tong, CHEN Zhang-yong, and CHENG Yong-mao
In order to reduce false-positive error probability and false-negative error probability for bills′ watermarks detection, an algorithm based on prior information and multi-template matching is proposed. By means of stepped-matching idea, it selects initial watermark template and uses single-template matching algorithm In order to reduce false-positive error probability and false-negative error probability for bills′ watermarks detection, an algorithm based on prior information and multi-template matching is proposed. By means of stepped-matching idea, it selects initial watermark template and uses single-template matching algorithm to find the approximate position of initial watermark template firstly. Secondly, it uses prior information to calculate watermarks′ scattering region. Thirdly, it uses multi-template matching algorithm to detect watermarks in the scattering region. Finally, it uses prior information to check the watermarks′ position that been detected, and to estimate the watermarks′ position that not been detected. The experiments show that the new algorithm can reduce the false-positive error probability and false-negative error probability, and it is effective to detect bills′ watermarks..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1706 (2010)
Image Denoising Algorithm Based on Bilateral Filtering and Dual-Tree Complex Wavelet
CAO Jian-zhong, ZHOU Zuo-feng, TANG Yao, GUO Min, and WANG Hao
An image denoising algorithm based on bilateral filtering and dual-tree complex wavelet transform is proposed.The noisy image is decomposed into multi-scale and multi-directional subbands by dual-tree complex wavelet transform,and each high-pass directional subband is denoised by local Wiener filtering with directionalAn image denoising algorithm based on bilateral filtering and dual-tree complex wavelet transform is proposed.The noisy image is decomposed into multi-scale and multi-directional subbands by dual-tree complex wavelet transform,and each high-pass directional subband is denoised by local Wiener filtering with directional windows.During the reconstruction,each low-pass constructed image is further denoised by the bilateral filtering in spatial domain.The experiment results show that the proposed image denoising algorithm achieves significant improvement of denoising performance..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1712 (2010)
Application for Visual Estimating Gamma of Computer Display on Internet
LI Qiong, SHI Jun-sheng, and ZHANG Zi-yang
Using the self-developed web-based gamma estimation software, experiments of visual estimating gamma are carried out on CRTs and LCDs through internet in three different view environments of dark, dim and office conditioning. The experimental results show that: 1) Estimation deviation of different subjects is less thanUsing the self-developed web-based gamma estimation software, experiments of visual estimating gamma are carried out on CRTs and LCDs through internet in three different view environments of dark, dim and office conditioning. The experimental results show that: 1) Estimation deviation of different subjects is less than 0.13 on CRTs, and less than 0.20 on LCDs respectively; 2) Compared with measured results, average error of estimated gamma is less than 0.07 on CRTs, and less than 0.17 on LCDs respectively; 3) Viewing environments do not effect results of visual estimating gamma; 4) Viewing angle has great influence on estimated gamma of LCDs; 5) The “luminance” and “contrast” setting of display does not effect result of visual estimating gamma..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1716 (2010)
Image Processing of Moiré Fringes of Measuring Focal Length of Lens Based on Talbot-Moiré
WU Ling-ling, WU Guo-jun, CANG yu-ping, and CHEN Liang-yi
Based on Talbot effect and Moiré fringes of Ronchi gratings,focal length measurement of the long focal length is carried out. The focal length of measured lens can be figured out accurately according to its relation to the slope coefficient of Moiré fringes. To get the slope of Moiré fringes, the image oBased on Talbot effect and Moiré fringes of Ronchi gratings,focal length measurement of the long focal length is carried out. The focal length of measured lens can be figured out accurately according to its relation to the slope coefficient of Moiré fringes. To get the slope of Moiré fringes, the image of Moiré fringes is mainly filtered or smoothed by mathematics morphological method to enhance the contrast of fringes effectively. Then the filtered image is processed by thinning to single pixel width. The fringes are labeled to fitting lines to calculate the slope coefficient accurately,and the error of focal length is 0.10%..
Acta Photonica Sinica
- Publication Date: Aug. 24, 2021
- Vol. 39, Issue 9, 1723 (2010)
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